text: /* ----------------------------------------------------------------------
   * Project:      CMSIS DSP Library
   * Title:        arm_cmplx_mult_real_q31.c
   * Description:  Q31 complex by real multiplication
   *
   * $Date:        18. March 2019
   * $Revision:    V1.6.0
   *
   * Target Processor: Cortex-M cores
   * -------------------------------------------------------------------- */
  /*
   * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
   *
   * SPDX-License-Identifier: Apache-2.0
   *
   * Licensed under the Apache License, Version 2.0 (the License); you may
   * not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "../../../CMSIS_DSP/Include/arm_math.h"
  
  /**
    @ingroup groupCmplxMath
   */
  
  /**
    @addtogroup CmplxByRealMult
    @{
   */
  
  /**
    @brief         Q31 complex-by-real multiplication.
    @param[in]     pSrcCmplx   points to complex input vector
    @param[in]     pSrcReal    points to real input vector
    @param[out]    pCmplxDst   points to complex output vector
    @param[in]     numSamples  number of samples in each vector
    @return        none
  
    @par           Scaling and Overflow Behavior
                     The function uses saturating arithmetic.
                     Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] are saturated.
   */
  
  void arm_cmplx_mult_real_q31(
    const q31_t * pSrcCmplx,
    const q31_t * pSrcReal,
          q31_t * pCmplxDst,
          uint32_t numSamples)
  {
          uint32_t blkCnt;                               /* Loop counter */
          q31_t in;                                      /* Temporary variable */
  
  #if defined (ARM_MATH_LOOPUNROLL)
  
    /* Loop unrolling: Compute 4 outputs at a time */
    blkCnt = numSamples >> 2U;
  
    while (blkCnt > 0U)
    {
      /* C[2 * i    ] = A[2 * i    ] * B[i]. */
      /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
  
      in = *pSrcReal++;
  #if defined (ARM_MATH_DSP)
      /* store saturated result in 1.31 format to destination buffer */
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
  #else
      /* store result in destination buffer. */
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
  #endif
  
      in = *pSrcReal++;
  #if defined (ARM_MATH_DSP)
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
  #else
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
  #endif
  
      in = *pSrcReal++;
  #if defined (ARM_MATH_DSP)
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
  #else
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
  #endif
  
      in = *pSrcReal++;
  #if defined (ARM_MATH_DSP)
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
  #else
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
  #endif
  
      /* Decrement loop counter */
      blkCnt--;
    }
  
    /* Loop unrolling: Compute remaining outputs */
    blkCnt = numSamples % 0x4U;
  
  #else
  
    /* Initialize blkCnt with number of samples */
    blkCnt = numSamples;
  
  #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
  
    while (blkCnt > 0U)
    {
      /* C[2 * i    ] = A[2 * i    ] * B[i]. */
      /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
  
      in = *pSrcReal++;
  #if defined (ARM_MATH_DSP)
      /* store saturated result in 1.31 format to destination buffer */
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
      *pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
  #else
      /* store result in destination buffer. */
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
      *pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
  #endif
  
      /* Decrement loop counter */
      blkCnt--;
    }
  
  }
  
  /**
    @} end of CmplxByRealMult group
   */
  